NASA missions continued their ground-breaking research on the Red Planet in 2011. These discoveries will help lay the foundation for future human missions to Mars. NASA’s Mars Reconnaissance Orbiter revealed possible flowing water during the planet’s warmest months. Dark, finger-like features appear and extend down some Martian slopes during late spring through summer, fade in winter, and return the next spring. Repeated observations tracked the seasonal changes in these recurring features on several steep slopes in the middle latitudes of Mars’ southern hemisphere. Scientists’ best explanation for these observations is the flow of briny water. Some aspects of the observations still puzzle researchers, but flows of liquid brine fit the features’ characteristics better than alternate hypotheses. These results are the closest scientists have come to finding evidence of liquid water on the planet’s surface today.
NASA’s Mars Exploration Rover program continued to make news in 2011. The Opportunity rover found bright veins of a mineral, apparently gypsum, deposited by water, near the rim of Endeavour crater. Analysis of the vein will help improve understanding of the history of wet environments on Mars. NASA’s newest Mars explorer, the Mars Science Laboratory spacecraft, which includes the car-sized Curiosity rover, launched aboard an Atlas V rocket on Nov. 26 to begin an eight-month journey to the Red Planet’s Gale Crater. The rover will search for signs that the planet could ever have been hospitable to life.